Answer
$$n=-\frac{8}{7}$$
$$n=4$$
Work Step by Step
We have $$3n(7n-20)=96$$
Expanding the expression and sending all the elements to the left side $$21n^2-60n-96 = 0$$ $$3(7n^2-20n-32)=0$$
Factorizing $$(n-4)(7n+8)=0$$
Solving each parenthesis 1)$$n-4=0$$ $$n=4$$
2) $$7n+8=0$$ $$7n=-8$$ $$n=-\frac{8}{7}$$
